| 摘要 |
Method and apparatus for amplification of amplitude-modulated, ultrasonic frequency, electronic signals providing superior loss-of-carrier signal detection. Low noise integrated circuits are employed to provide high amplification of low level input signals without adding appreciable electrical noise during the amplification process. An automatic gain control (AGC) circuit ensures a nearly constant level of ultrasonic signal amplitudes from the amplifier without excessive amplification of electrical noise under conditions of low applied input signals. The electrical noise, inherent in the system, has only minimal effect on the loss-of-carrier detector.
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